Hormetic effect and mechanism of imidazolium-based ionic liquids on the nematode Caenorhabditis elegans

Intermittent multi-generational reproductive toxicities of 1-alkyl-3-methylimidazolium tetrafluoroborate with essential involvement of lipid metabolism

Ionic liquids (ILs) become emerging environmental pollutants. Especially, alkyl imidazolium ILs commonly showed stimulation in toxicological studies and mechanisms remained to be explored. In the present study, alkyl imidazolium tetrafluoroborate ([amim]BF4), with ethyl ([emim]), hexyl ([hmim]) and octyl ([omim]) as side-chains, were chosen as target ILs. Their toxicities on the reproduction and lifespan of Caenorhabditis elegans were explored with two types (A and B) exposure arrangements to mimic realistic intermittent multi-generational exposure scenarios. In type A scenario, there was an exposure every 4 generations with 12 generations in total, and in type B one, there was an exposure every two generations with 12 generations in total. Result showed that [emim]BF4 caused inhibition on the reproduction in 8 generations in type A exposure but 6 ones in type B exposure. Meanwhile, [hmim]BF4 showed inhibition in one generation and stimulation in 3 generations in type A exposure, but stimulation in 6 generations in type B exposure. Also, [omim]BF4 showed stimulation in one generation in type B exposure. Collectively, the results demonstrated less frequencies of inhibition, or more frequencies of stimulation, in the exposure scenario with more frequent exposures. Further mechanism exploration was performed to measure the lipid storage and metabolism in the aspect of energy supply. Results showed that [emim]BF4, [hmim]BF4 and [omim]BF4 commonly stimulated the triglyceride (TG) levels across generations. They also disturbed the activities of glycerol-3-phosphate acyltransferase (GPAT) and acetyl CoA carboxylase (ACC) in lipogenesis, those of adipose triglyceride lipase (ATGL) and carnitine acyl transferase (CPT) in lipolysis, and also the contents of acetyl-CoA (ACA). Further data analysis indicated the energy allocation among life traits including reproduction, antioxidant responses and hormone regulations.

Mechanisms of Biological Effects of Ionic Liquids: From Single Cells to Multicellular Organisms

The review presents a detailed discussion of the evolving field studying interactions between ionic liquids (ILs) and biological systems. Originating from molten salt electrolytes to present multiapplication substances, ILs have found usage across various fields due to their exceptional physicochemical properties, including excellent tunability. However, their interactions with biological systems and potential influence on living organisms remain largely unexplored. This review examines the cytotoxic effects of ILs on cell cultures, biomolecules, and vertebrate and invertebrate organisms. Our understanding of IL toxicity, while growing in recent years, is yet nascent. The established findings include correlations between harmful effects of ILs and their ability to disturb cellular membranes, their potential to trigger oxidative stress in cells, and their ability to cause cell death via apoptosis. Future research directions proposed in the review include studying the distribution of various ILs within cellular compartments and organelles, investigating metabolic transformations of ILs in cells and organisms, detailed analysis of IL effects on proteins involved in oxidative stress and apoptosis, correlation studies between IL doses, exposure times and resulting adverse effects, and examination of effects of subtoxic concentrations of ILs on various biological objects. This review aims to serve as a critical analysis of the current body of knowledge on IL-related toxicity mechanisms. Furthermore, it can guide researchers toward the design of less toxic ILs and the informed use of ILs in drug development and medicine.

Hormesis determines lifespan

This paper addresses how long lifespan can be extended via multiple interventions, such as dietary supplements [e.g., curcumin, resveratrol, sulforaphane, complex phytochemical mixtures (e.g., Moringa, Rhodiola)], pharmaceutical agents (e.g., metformin), caloric restriction, intermittent fasting, exercise and other activities. This evaluation was framed within the context of hormesis, a biphasic dose response with specific quantitative features describing the limits of biological/phenotypic plasticity for integrative biological endpoints (e.g., cell proliferation, memory, fecundity, growth, tissue repair, stem cell population expansion/differentiation, longevity). Evaluation of several hundred lifespan extending agents using yeast, nematode (Caenorhabditis elegans), multiple insect and other invertebrate and vertebrate models (e.g., fish, rodents), revealed they responded in a manner [average (mean/median) and maximum lifespans] consistent with the quantitative features [i.e., 30-60% greater at maximum (Hormesis Rule)] of the hormetic dose response. These lifespan extension features were independent of biological model, inducing agent, endpoints measured and mechanism. These findings indicate that hormesis describes the capacity to extend life via numerous agents and activities and that the magnitude of lifespan extension is modest, in the percentage, not fold, range. These findings have important implications for human aging, genetic diseases/environmental stresses and lifespan extension, as well as public health practices and long-term societal resource planning.

Anti-Aging Effect of Hemerocallis citrina Baroni Polysaccharide-Rich Extract on Caenorhabditis elegans

Plant polysaccharides are important for anti-aging research. Polysaccharides from Hemerocallis citrina Baroni (H. citrina) have been reported to have antioxidant activity; however, their anti-aging roles and mechanisms are not clear. In this study, we extracted polysaccharides from H. citrina by an ultrasonic-assisted water extraction-alcohol precipitation method and chemically determined the physicochemical properties such as extraction yield, content, and in vitro antioxidant properties of H. citrina polysaccharide-rich extract (HCPRE). Using Caenorhabditis elegans (C. elegans) as a model animal, the anti-aging effect of HCPRE was investigated, and the mechanism of action of HCPRE was explored by the in vivo antioxidant level assay of C. elegans and the related gene expression assay. The extraction yield of HCPRE was 11.26%, the total polysaccharide content was 77.96%, and the main monosaccharide components were glucose and galactose. In addition, HCPRE exhibited good antioxidant activity both in vitro and in vivo. Under normal thermal stress and oxidative stress conditions, being fed 1200 µg/mL of HCPRE significantly prolonged the life span of C. elegans by 32.65%, 17.71%, and 32.59%, respectively. Our study showed that HCPRE exerted an anti-aging effect on C. elegans, and its mechanism involves increasing the activities of catalase (CAT) and superoxide dismutase (SOD), reducing the level of reactive oxygen species (ROS) and regulating the expression of related genes.

Hormone-mediated multi- and trans-generational reproductive toxicities of 1-ethyl-3-methylimidazolium hexafluorophosphate on Caenorhabditis elegans

Ionic liquids (ILs) are emergent pollutants and their reproductive toxicities show hormesis, earning attentions on their environmental risk. Yet, their reproductive effects over generations and the mechanisms were seldom explored. In the present study, the reproductive effects of 1-ethyl-3-methylimidazolium hexafluorophosphate ([C₂mim]PF₆) on Caenorhabditis elegans were measured in 11 continuously exposed generations (F1 to F11) to explore the multi-generational effects, and also in the non-exposed generations of F1 and F11 (i.e., their great-grand-daughters, T4 and T4') to explore the trans-generational effects. In multi-generational reproductive effects, there were concentration-dependent hormetic effects with hazard-benefit alteration between low and high concentrations (e.g., in F3). There were also generation-dependent hormetic effects with hazard-benefit alterations over generations (e.g., between F4 and F5, between F8 and F9, and between F10 and F11). Meanwhile, the results also showed benefit-hazard alteration between F2 and F3, between F6 and F7, and between F9 and F10. Trans-generational effects showed common inhibitions in T4 and T4' at both low and high concentrations. In the biochemical analysis, hormones and hormone-like substances including progesterone (P), estradiol (E2), prostaglandin (PG) and testosterone (T) showed multi- and trans-generational changes with inhibition and stimulation, which contributed to the reproductive outcomes in each generation. Such contribution was also observed in the hormones' precursor cholesterol and the proteins that are essential for reproduction including vitellogenin (Vn) and major sperm protein (MSP). Moreover, the biochemicals showed significant involvement in the connection among generations. Furthermore, the multi- and trans-generational effects of [C₂mim]PF₆ and histidine showed similar modes of actions despite some differences, implying the contribution of their shared imidazole structure.

Rhodobacter sphaeroides as a model to study the ecotoxicity of 1-alkyl-3-methylimidazolium bromide

The purple non-sulfur bacterium Rhodobacter sphaeroides was selected as a biological model to investigate its response to the toxicity of 1-alkyl-3-methylimidazolium bromide ([C_nmim]Br), a type of ionic liquid (IL), with different alkyl chain lengths (n describes the number of carbon atoms in the alkyl chain). The inhibition of bacterial growth by [C_nmim]Br was positively correlated with n. Morphological characterization revealed that [C_nmim]Br caused cell membrane perforation. The signal amplitude of the electrochromic absorption band shift of endogenous carotenoids showed a negatively linear correlation with n, and the amplitude of the blue-shift of the B850 band in light-harvesting complex 2 showed a positively linear correlation with n. Furthermore, an increase in blocked ATP synthesis and increase in antioxidant enzyme activity were observed in chromatophores treated with ILs containing longer alkyl chains. In summary, the purple bacterium can be developed as a model to monitor ecotoxicity and examine the mechanism of IL toxicity.

Detoxification of ionic liquids using glutathione, cysteine, and NADH: Toxicity evaluation by Tetrahymena pyriformis

Ionic liquids (ILs), also known as green solvents, are widely acknowledged in several fields, such as chemical separation, synthesis, and electrochemistry, owing to their excellent physiochemical properties. However, their poor biodegradability may lead to environmental and health risks, posing a severe threat to humans, thus requiring further research. In this study, the biotoxicities of the imidazolium-based ILs were evaluated in Tetrahymena pyriformis. Moreover, IL detoxification was investigated by addition of glutathione (GSH), cysteine, and nicotinamide adenine dinucleotide (NADH). Reactive oxygen species (ROS) initiated by different IL types caused damage to Tetrahymena, while glutathione, cysteine, and NADH eliminated ROS, achieving the detoxification purposes. Detoxification results showed that NADH exhibited the best detoxification ability, followed by glutathione and cysteine. Finally, RT-PCR results suggested that metallothionein might have participated in IL detoxification.

Antimicrobial and Toxicity Evaluation of Imidazolium-Based Dicationic Ionic Liquids with Dicarboxylate Anions

Imidazolium-based dicationic ILs (DILs) presenting antimicrobial activity and relatively low toxicity are highly desirable and are envisioned for use in live tissue to prevent bacterial or fungal infections. In this context, we present here DILs with dicarboxylate anions [C_n(MIM)₂[C_n(MIM)₂][CO₂-(CH₂)_mCO₂], in which n = 4, 6, 8, and 10, and m = 0, 1, 2, 3, 4, and 5. The results showed that DILs with an alkyl chain spacer of ten carbons were active against yeasts and the bacterial strains tested. However, most of the DILs were cytotoxic and toxic at 1 mM. By contrast, DILs with alkyl chains possessing less than ten carbons were active against some specific Candidas and bacteria (mainly S. aureus), and they showed moderate cytotoxicity. The best activity against Gram-positive bacteria was observed for [C₄(MIM)₂][Pim] toward MRSA. For the DILs described herein, their level of toxicity against C. elegans was lower than that of most of the mono- and dicationic IL analogs with other anions. Our results showed that the presence of carboxylate anions reduces the toxicity of DILs compared to DILs containing halide anions, which is particularly significant to the means of designing biologically active compounds in antimicrobial formulations.

Reproductive toxicities of 1-ethyl-3-methylimidazolium bromide on Caenorhabditis elegans with oscillation between inhibition and stimulation over generations

Ionic liquids (ILs) become emerging pollutants and their toxicities earn increasing attentions. Yet, their effects were seldom explored on reproduction which connects generations and also effects across generations. In the present study, reproductive effects of 1-ethyl-3-methylimidazolium bromide ([C₂mim]Br), one representative IL, were studied on C. elegans with 11 continuously exposed generations (F1 to F11). At 8.20E-5 g/L, the effects on the initial reproduction showed oscillatory changes between stimulation (in F1, F3, F4, F6 and F10) and inhibition (in F2, F5, F7, F8 and F11). At 8.20E-3 g/L, the effects on the reproduction over generations also showed such oscillation despite of different stimulation or inhibition levels, and even opposite influences in F4 and F11. The effects of [C₂mim]Br on the total reproduction also showed the concentration-dependent oscillation between stimulation and inhibition over generations, though they had less alteration frequencies than those on the initial reproduction. Biochemical and molecular indicators were further measured in F1, F4, F7 and F11 to explore potential mechanisms. Results showed that the effects on spermatocyte protein 8 (SPE8) showed positive correlation with those on reproduction while the influences on major sperm protein (MSP) and sperm transmembrane protein 9 (SPE9) showed negative correlation with SPE8. Moreover, the dysregulation on expressions of acs-2 and akt-1 indicated the involvement of glucolipid metabolism. The changes in expressions of set-2, met-2, set-25 and mes-4 demonstrated that the long-term reproductive impacts of [C₂mim]Br over generations also involved histone methylation at H3K4, H3K9 and H3K36, which also connected with the glucolipid metabolism.

Novel Pathway for Vanadium(V) Bio-Detoxification by Gram-Positive Lactococcus raffinolactis

Whereas prospects of bioremediation for a vanadium(V) [V(V)]-contaminated environment are widely recognized, reported functional species are extremely limited, with the vast majority of Gram-negative bacteria in Proteobacteria. Herein, the effectiveness of V(V) reduction is proved for the first time by Lactococcus raffinolactis, a Gram-positive bacterium in Firmicutes. The V(V) removal efficiency was 86.5 ± 2.17% during 10-d operation, with an average removal rate of 4.32 ± 0.28 mg/L·d in a citrate-fed system correspondingly. V(V) was bio-reduced to insoluble vanadium(IV) and distributed both inside and outside the cells. Nitrite reductase encoded by gene nirS mainly catalyzed intracellular V(V) reduction, revealing a previously unrecognized pathway. Oxidative stress induced by reactive oxygen species from dissimilatory V(V) reduction was alleviated through strengthened superoxide dismutase and catalase activities. Extracellular polymeric substances with chemically reactive hydroxyl (-OH) and carboxyl (-COO^-) groups also contributed to V(V) binding and reduction as well as ROS scavenging. This study can improve the understanding of Gram-positive bacteria for V(V) bio-detoxification and offer microbial resources for bioremediation of a V(V)-polluted environment.

Life stage-dependent toxicities of 1-ethyl-3-methylimidazolium bromide on Caenorhabditis elegans

Ionic liquids (ILs) are considered as extracting solvents in soil remediation. However, they can be pollutants themselves, and their own toxicities are of concerns. Notably, organisms were exposed to pollutants at random life stages in actual environmental exposure scenario, which is different from the set-up of one uniform life stage in usual experiment designs. The influence of life stages on ILs toxicities will provide essential information on their actual environmental risks. In the present study, effects of 1-ethyl-3-methylimidazolium bromide ([C₂mim]Br) were measured on C. elegans with egg exposure and adult exposure. In egg exposure, [C₂mim]Br increased the lifespan, stimulated initial reproduction and inhibited the total reproduction. Biochemical indices including oxidative stress, antioxidant responses and oxidative damage were further measured to explore the toxicity mechanisms. Results showed that [C₂mim]Br significantly stimulated O₂^-· as the oxidative stress and superoxide dismutase (SOD) as the antioxidant defense. In adult exposure, [C₂mim]Br inhibited initial reproduction, total reproduction and lifespan. Biochemical results showed that [C₂mim]Br significantly stimulated H₂O₂ and oxidized glutathione (GSSG). The overall findings demonstrated that [C₂mim]Br caused life stage-dependent toxicities on C. elegans. Future studies are still needed for the detailed mechanisms.

Alteration in concentration-response curves of four N-alkylpyridinium chloride by exposure concentration, time and in their mixtures by uniform design

The concentration-response curves (CRCs) of chemicals are important in extrapolating their effects from laboratory studies to their risk assessment in the field. Yet, the CRCs can be altered by exposure concentration and mixture conditions, and also by exposure time in recent reports. Presently, ionic liquids (N-alkylpyridinium chloride, [apyr]Cl) were used for CRC-alteration studies. In individual effects on Vibrio qinghaiensis sp. Q67 (Q67) from 0.25 to 24 h, the CRCs of [epyr]Cl and [bpyr]Cl changed from S- to J-shaped with decreases in inhibition and increases in stimulation, while the CRCs of [hpyr]Cl changed from S- to flat-shape with decreases in inhibition but without stimulation. In mixture effects on Q67, the CRCs all changed from S- to J-shaped from 0.25 to 24 h. By means of the variable selection and modeling method based on the prediction (VSMP), the CRC-alterations of mixtures were positively contributed by [epyr]Cl but negatively contributed by [bpyr]Cl. Furthermore, a parameter was developed by the area of a triangular that combined acute inhibition (EC_50,0.25h) and chronic stimulation (Zero-effect Point, i.e., ZEP_24h and the minimum inhibition effect, i.e., E_min,24h). This parameter successfully evaluated the CRC-alterations in both individual and mixture effects over time, and indicated potential interactions in CRC-alteration in mixtures.

Alteration between inhibition and stimulation in individual and mixture effects of [amim]Br and [apyr]Br on Aliivibrio fischeri: Time and side-chain dependence

The exposure reality of chemicals is usually in mixtures, the effects of which are usually extrapolated from individual results. Yet, such extrapolation is challenged by the alteration between monotonic concentration-response curves (CRCs) and non-monotonic hormetic CRCs in individual and mixture effects. In the present study, we aimed to investigate the occurrence of such alterations using 1-alkylimidazolium bromide ([amim]Br) and 1-alkylpyridinium bromide ([apyr]Br) ionic liquids (ILs) as model chemicals. Effects of four [amim]Br, four [apyr]Br, and their quaternary mixtures designed by uniform design were measured on Aliivibrio fischeri in a time-dependent fashion. Results showed that the individual [amim]Br showed monotonic CRCs. Their inhibition increased over the length of the side-chain and decreased over the exposure time. The [amim]Br mixtures showed non-monotonic hormetic CRCs, where the stimulations increased over exposure time. The individual [apyr]Br had non-monotonic hormetic CRCs, and their stimulation increased over the length of the side-chain. Meanwhile, the [apyr]Br mixtures had monotonic CRCs without any stimulation. Notably, the positive contributors to the mixture effects were [emim]Br or [epyr]Br which had the shortest side-chain among the components. The findings can facilitate accurate prediction on the environmental effects of ILs with specific considerations on hormetic and mixture effects.

Using an interpolation-based method (IDVequ) to predict the combined toxicities of hormetic ionic liquids

In the field of computational toxicology, predicting toxicological interaction or hormesis effect of a mixture from individuals is still a challenge. The two most frequently used model concentration addition (CA) and independent action (IA) also cannot solve these challenges perfectly. In this paper, we used IDV_equ (an interpolation method based on the Delaunay triangulation and Voronoi tessellation as well as the training set of direct equipartition ray design (EquRay) mixtures) to predict the toxicities of binary mixtures composed of hormetic ionic liquids (ILs). One of the purposes is to verify the predictive ability of IDV_equ. The other one is to improve the risk assessment of ILs mixtures especial hormetic ILs, because the toxicity reports of ILs mixtures are rarely reported in particular the toxicity of the hormetic ILs mixtures. Hence, we determined time-dependent toxicities of four ILs and their binary mixtures (designed by EquRay) to Vibrio qinghaiensis sp.-Q67 at first. Then, mixture toxicities were predicted and compared using the IDV_equ and CA. The results show that, the accuracy of IDV_equ is higher than the accuracy of CA. And, more important, to some mixtures out of the CA application, IDV_equ also can predict the mixture effects accurately. It showed that IDV_equ can be applied to predict the toxicity of any binary mixture regardless of the type of concentration-response curve of the components. These toxicity data provided useful information for researching the prediction of hormesis or toxicological interaction of the mixture and toxicities of ILs mixtures.

Toxic effects of prolonged exposure to [C14mim]Br on Caenorhabditis elegans

Ionic liquids (ILs) are gradually concerned due to their potential environmental and health risks. In this work, the chronic effects of imidazolium-based ILs, using [C₁₄mim]Br as a representative, were evaluated using model animal Caenorhabditis elegans. Our results show that prolonged exposure (72 h) of ILs to the nematodes at concentrations of 5 and 10 mg/L induced adverse effects on the growth, locomotive behaviors and development. To explore the toxicity mechanism, lipofuscin content, ROS level and the expressions of five superoxide dismutase (SOD) genes were determined after the prolonged exposure. The lipofuscin content, ROS level and expressions of SOD genes did not show significant changes except that the expression of sod-5 was reduced by 2.7-fold following the treatment of 10 mg/L of [C₁₄mim]Br. These results suggest that oxidative stress may not be responsible for the adverse physiological effects induced by relatively low concentrations of imidazolium-based ILs. We further determined the gene expressions of phase I detoxification enzyme cytochrome P450 (CYP), phase II detoxification enzyme UDP-glucuronosyltransferase (UGT) and ATP-binding cassette (ABC) transporter P-glycoprotein (PGP). The results demonstrate that CYP, UGT and PGP may be involved in the detoxification of ILs. Our findings will aid in understanding the mechanisms of both toxicity and detoxification of imidazolium-based ILs in animals.

Biosafety assessment of water samples from Wanzhou watershed of Yangtze Three Gorges Reservior in the quiet season in Caenorhabditis elegans

We here employed a model animal of Caenorhabditis elegans to perform toxicity assessment of original surface water samples collected from Three Gorges Reservoir (TGR) in the quiet season in Wanzhou, Chongqing. Using some sublethal endpoints, including lifespan, body length, locomotion behavior, brood size, and intestinal reactive oxygen species (ROS) induction, we found that the examined five original surface water samples could not cause toxicity on wild-type nematodes. Nevertheless, the surface water sample collected from backwater area induced the significant increase in expressions of genes (sod-2 and sod-3) encoding Mn-SODs in wild-type nematodes. Among the examined five original surface water samples, exposure to the original surface water sample collected from backwater area could further cause the toxicity in decreasing locomotion behavior and in inducing intestinal ROS production in sod-3 mutant nematodes. Moreover, the solid phase of surface water sample collected from backwater area might mainly contribute to the observed toxicity in sod-3 mutant nematodes. Our results are helpful for understanding the potential effects of surface water in the TGR region in the quiet season on environmental organisms.

The toxicity of ionic liquid 1-decylpyridinium bromide to the algae Scenedesmus obliquus: Growth inhibition, phototoxicity, and oxidative stress

Although ionic liquids (ILs) are unlikely to act as air contaminants, their high solubility and slow degradation make them a potential threat to the aquatic environment. The IL 1-decylpyridinium bromide ([DPy]Br) is a common type of pyridine IL, which has varied applications such as in extraction, separation, and catalytic synthesis. Herein, the toxicity of [DPy]Br to S. obliquus is determined. Growth was inhibited by high-concentration [DPy]Br, whereas it had a hormetic effect at low concentrations. The IC_50-96h was approximately 0.06mg/L. The cell membrane permeability of S. obliquus increased with [DPy]Br concentration, indicating that [DPy]Br can cause damage to the algae cell structure. Chlorophyll content decreased at high [DPy]Br concentration; chlorophyll fluorescence parameters, such as the maximum effective quantum yield of PSII (F_v/F_m), potential activity of PSII (F_v/F₀), yield of the photochemical quantum [Y(II)], and the non-photochemical quenching coefficient (NPQ) were affected, suggesting that [DPy]Br can damage PSII. The ROS fluorescent images revealed that the morphology of cells changed gradually from fusiform to round. High ROS levels were observed with high concentrations of [DPy]Br, indicating that [DPy]Br induced oxidative stress on S. obliquus. The SOD and CAT activities increased when the concentration was lower than IC₅₀, whereas they decreased when the concentration was higher than IC₅₀. The relative ROS content was significantly correlated with growth inhibition rate, cell membrane permeability, chlorophyll content, and SOD and CAT activities. The increase of ROS content in algal cells is an important toxicological mechanism of [DPy]Br to S. obliquus.

Molecular basis for oxidative stress induced by simulated microgravity in nematode Caenorhabditis elegans

Caenorhabditis elegans is an important in vivo assay system for toxicological studies. Herein, we investigated the role of oxidative stress and the underlying molecular mechanism for induced adverse effects of simulated microgravity. In nematodes, simulated microgravity treatment induced a significant induction of oxidative stress. Genes (mev-1, gas-1, and isp-1) encoding a molecular machinery for the control of oxidative stress were found to be dysregulated in simulated microgravity treated nematodes. Meanwhile, genes (sod-2, sod-3, sod-4, sod-5, aak-2, skn-1, and gst-4) encoding certain antioxidant defense systems were increased in simulated microgravity treated nematodes. Mutation of mev-1, gas-1, sod-2, sod-3, aak-2, skn-1, or gst-4 enhanced susceptibility to oxidative stress induced by simulated microgravity, whereas mutation of isp-1 induced a resistance to oxidative stress induced by simulated microgravity. Mutation of sod-2, sod-3, or aak-2 further suppressed the recovery effect of simulated microgravity toxicity in nematodes after simulated microgravity treatment for 1h. Moreover, administration of ascorbate could inhibit the adverse effects including the induction of oxidative stress in simulated microgravity treated nematodes. Mutation of any of the genes encoding metallothioneins or the genes of hsp-16.1, hsp-16.2 and hsp-16.48 encoding heat-shock proteins did not affect the induction of oxidative stress in simulated microgravity treated nematodes. Our results provide a molecular basis for the induction of oxidative stress in simulated microgravity treated organisms.

Insights into the differential toxicological and antioxidant effects of 4-phenylchalcogenil-7-chloroquinolines in Caenorhabditis elegans

Organic selenium and tellurium compounds are known for their broad-spectrum effects in a variety of experimental disease models. However, these compounds commonly display high toxicity and the molecular mechanisms underlying these deleterious effects have yet to be elucidated. Thus, the need for an animal model that is inexpensive, amenable to high-throughput analyses, and feasible for molecular studies is highly desirable to improve organochalcogen pharmacological and toxicological characterization. Herein, we use Caenorhabdtis elegans (C. elegans) as a model for the assessment of pharmacological and toxicological parameters following exposure to two 4-phenylchalcogenil-7-chloroquinolines derivatives (PSQ for selenium and PTQ for tellurium-containing compounds). While non-lethal concentrations (NLC) of PTQ and PSQ attenuated paraquat-induced effects on survival, lifespan and oxidative stress parameters, lethal concentrations (LC) of PTQ and PSQ alone are able to impair these parameters in C. elegans. We also demonstrate that DAF-16/FOXO and SKN-1/Nrf2 transcription factors underlie the mechanism of action of these compounds, as their targets sod-3, gst-4 and gcs-1 were modulated following exposures in a daf-16- and skn-1-dependent manner. Finally, in accordance with a disturbed thiol metabolism in both LC and NLC, we found higher sensitivity of trxr-1 worm mutants (lacking the selenoprotein thioredoxin reductase 1) when exposed to PSQ. Finally, our study suggests new targets for the investigation of organochalcogen pharmacological effects, reinforcing the use of C. elegans as a powerful platform for preclinical approaches.

The time-dependent synergism of the six-component mixtures of substituted phenols, pesticides and ionic liquids to Caenorhabditis elegans

Traditional environmental risk assessment rarely focused on exposures to multi-component mixtures which may cause toxicological interactions and usually ignored that toxicity is a process in time, which may underestimate the environment risk of mixtures. In this paper, six chemicals belonging to three categories, two substituted phenols, two pesticides and two Ionic liquids, were picked to construct a six-component mixture system. To systematically examine the effects of various concentration compositions, the uniform design ray method was employed to design nine mixture rays with nine mixture ratios and for every mixture ray 12 concentration levels were specified by the fixed ratio ray design. The improved combination index was used to evaluate the combined toxicities of the mixtures to Caenorhabditis elegans (C. elegans) in the exposure times of 6, 12 and 24h. It was shown that the mixture rays display time-dependent synergism, i.e. the range of synergistic effect narrows and the strength of synergism runs down with exposure time, which illustrates that the mixture toxicity of some chemicals is not a sum of individual toxicities at some exposure times and it is necessary to consider the toxicological interaction in mixtures.

Biological Activity of Ionic Liquids and Their Application in Pharmaceutics and Medicine

Ionic liquids are remarkable chemical compounds, which find applications in many areas of modern science. Because of their highly tunable nature and exceptional properties, ionic liquids have become essential players in the fields of synthesis and catalysis, extraction, electrochemistry, analytics, biotechnology, etc. Apart from physical and chemical features of ionic liquids, their high biological activity has been attracting significant attention from biochemists, ecologists, and medical scientists. This Review is dedicated to biological activities of ionic liquids, with a special emphasis on their potential employment in pharmaceutics and medicine. The accumulated data on the biological activity of ionic liquids, including their antimicrobial and cytotoxic properties, are discussed in view of possible applications in drug synthesis and drug delivery systems. Dedicated attention is given to a novel active pharmaceutical ingredient-ionic liquid (API-IL) concept, which suggests using traditional drugs in the form of ionic liquid species. The main aim of this Review is to attract a broad audience of chemical, biological, and medical scientists to study advantages of ionic liquid pharmaceutics. Overall, the discussed data highlight the importance of the research direction defined as "Ioliomics", studies of ions in liquids in modern chemistry, biology, and medicine.